[ML] Transforms: Fix waiting state in transforms list.

[walterra]

Summary

Follow up to #93956.
Fixes #98444.
Fixes #74837.

When no transform nodes are available, existing continuous transform end up in a waiting state. This PR adds support for this state in the transforms UI. Without the fix, transforms in a waiting state would fail to show up in the transform list.

The waiting state was added in Elasticsearch here: elastic/elasticsearch#70139

Testing instructions:

• With the transform role enabled, create and start a continuous transform
• Quit ES and change its config to not include the transform role like:

node.roles: [
  "master",
  "data",
  "data_content",
  "data_hot",
  "data_warm",
  "data_cold",
  "data_frozen",
  "ingest",
  "ml",
  "remote_cluster_client",
  # "transform",
]

• Start ES+Kibana again, you should see the continuous transform in waiting state:

Checklist

• Unit or functional tests were updated or added to match the most common scenarios
• This was checked for breaking API changes and was labeled appropriately

[elasticmachine]

Pinging @elastic/ml-ui (:ml)

[peteharverson]

Tested and LGTM

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: a1c14f3
• Storybooks Preview

Metrics [docs]

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
transform	910.1KB	910.2KB	+123.0B

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream

cc @walterra

[kibanamachine]

💚 Backport successful

Status	Branch	Result
✅	7.13
✅	7.x

The backport PRs will be merged automatically after passing CI.